Dye-sensitized solar cell
In 1991 at EPFL in Switzerland, Michael Graetzel first discovered this cell, so it is also called Graetzel. The basic titania based DSC cell consists of a sandwich of TiO2, dye, electrolyte and catalyst between two conductive transparent electrodes. Upon illumination of the cell, charge separation occurs by electron injection from the excited state dye molecule into the conduction band of TiO2. Simply, light excites the dye, sending an electron on its way to be picked up and transmitted by the semiconducting titania to become electrical energy. The dye is then reduced by an electron transferred by the redox couple.
Dye-sensitized solar cell is a new type solar cell which differs from conventional photovoltaics as follows: Itisa photoelectrochemical cell: charge separation occurs on interface between a wide bandgap semiconductor and an electrolyte. It is a nanoparticulate titania cell: it is not a dense film as is amorphous silicon, but a “ light sponge”. It is a dye-sensitized cell: a dye monolayer chemically adsorbed on the semiconductor is a primary absorber of sunlight; free charge carriers are generated by electron injections from a dye molecule, excited by visible radiation.
Much less sensitive to angle of incidence of radiation good in refracted and reflected light. Performs over a much wider range of light conditions due to the high internal surface of titania(“light sponge”)-can be designed for operation at very low light. Can be designed to operate optimally over a wide range of temperatures.Much less sensitive to a partial shadowing. Option for transparent modules-so can be used for daylighting, roof lighting, displays. DSC production needs only commonly available non vacuum processing equipment, making it vastly cheaper to set up facilities. DSC has significantly lower embodied energy than all other forms of solar cell.
The DSC development in IPP:
In 2004, we establish the fist 500W DSC primary power station in the world.